So... Sigma get really interesting again! Three lenses get the OS treatment, and a new 8-16 ultra wide zoom for crop sensors. 85/1.4 could be very interesting if they continue as they have done with other recent primes.

Historically they have had non-constant aperture EX lenses, and it does seem an inconsistency if the predecessor model was but the replacement isn't, assuming they're the same performance.

There's the big question - is the performance the same? If not, better or worse? The current version is 20 elements in 16 groups, and the OS version is shown as 22 elements in 16 groups. The increase is not unexpected due to the OS mechanism, but the arrangement is different internally regardless.

There's the big question - is the performance the same? If not, better or worse? The current version is 20 elements in 16 groups, and the OS version is shown as 22 elements in 16 groups. The increase is not unexpected due to the OS mechanism, but the arrangement is different internally regardless.

Don't forget that they've added two FLD elements, which should help with correcting chromatic abberations. One of the things that I notice when pixel peeping is that the Sigma 70-200mm exhibits some amount of blue fringing and blooming at high contrast areas. Perhaps this will fix that issue?

I'm looking forward to the 8-16mm, 17-50mm and new 70-200mm. When those are released, I'm going to get calls from divorce lawyers ...